We plan to continue our investigation of the pathogenesis of fever in animal models of delayed hypersensitivity (DH) and immediate (antibody-mediated) hypersensitivity. We hope to determine the type of lymphocyte (T or B cells) as well as to characterize the lymphokine that mediates fever in DH and determine its relationship to other known lymphokines. In other studies, we plan to study various agents that activate other phagocytic functions in inflammation (e.g. chemotaxis, and metabolic changes) to see if they also induce endogenous pyrogen (EP) production in vitro. We will also compare EP release with other activities of phagocytic cells (granulocytes and monocytes) incubated with various activators and modulators of cell function to enlarge our understanding of the correlation of fever with inflammation in disease.